1. Field
The following description relates to a digital X-ray detector for obtaining a digital image using a Thin Film Transistor (TFT) without a film.
2. Description of the Related Art
A conventional X-ray image photographing system is used in a medical industry to photograph a subject onto a film and, and the resulting film needs to be printed for diagnosis. However, many research and studies have been conducted recently to develop a digital X-ray detector for obtaining a digital image using a TFT without a film.
For example, a digital X-ray detector may have an X-ray detection array which is fixed onto an external case thereof. At this time, the X-ray detection array includes a glass substrate, a TFT laminated on the glass substrate, a light converting material layer of amorphous selenium laminated on the TFT, an insulating layer formed on the light converting material layer and top electrodes formed on the insulating layer.
When the X-ray detection array is irradiated with X-rays, the X-ray produces electron-hole pairs in the light converting material layer. The electron-hole pairs are accelerated by power which is applied to top electrodes, so that the electrons may be transferred to external electrodes and the holes may be charged in a headacity of the TFT via upper electrodes of the TFT. Then, the TFT is switched on and off, an X-ray detection image may be obtained.
However, the above-mentioned digital X-ray detector are highly likely to be exposed to external forces since the X-ray image photographing system is often used outside. For example, while being moved or used, the digital X-ray detector may fall over or an external force may be imposed thereon.
In such cases, elements of the digital X-ray detector, such as a light converting material layer, a TFT and a glass substrate, may be damaged, thereby affecting performance of the digital X-ray detector. For this reason, it is required to come up with a measure to protect the X-ray detection array from a shock.